Phyllodiscus

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Phyllodiscus semoni
Phyllodiscus semoni holotype.jpg
Holotype of Phyllodiscus semoni
(drawn from a preserved specimen)
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Cnidaria
Class: Anthozoa
Order: Actiniaria
Family: Aliciidae
Genus: Phyllodiscus
Kwietniewski, 1897 [1]
Species:
P. semoni
Binomial name
Phyllodiscus semoni
Kwietniewski, 1897 [2]

Phyllodiscus is a monotypic genus of sea anemones in the family Aliciidae. The only species is Phyllodiscus semoni, commonly known as the night anemone, which is native to shallow seas in the central Indo-West Pacific, such as Indonesia, the Philippines and southern Japan. It is venomous and can cause a painful, long-lasting sting to humans. It is called unbachi-isoginchaku in Japanese which translates as "wasp-sea anemone". [3]

Contents

Description

Phyllodiscus semoni has a broad basal disc attached to the substrate. The lower portion of the column is smooth and the middle section has a radially arranged series of pseudo-tentacles, thick, stalked and branched outgrowths which show great variety in their appearance between different individuals. There are a number of hemispherical vesicles on the branches, and occasionally on the stalks. These contain nematocysts containing short and long-shafted stinging threads. The upper section of the column is short and smooth with a few nematocysts. The oral disc has a marginal ring of up to 160 long tentacles, two siphonoglyphs (feeding grooves) and a central mouth. [4]

Behaviour

A = Branched morphotype with pseudotentacles (arrows show vesicles)
B = Smooth disc morphotype Phyllodiscus semoni1.jpg
A = Branched morphotype with pseudotentacles (arrows show vesicles)
B = Smooth disc morphotype

There are a range of different morphotypes of this sea anemone. Some are smooth discs, some are similar to branching corals and others to dead coral rock covered by algae, resembling these models not only in shape, but also in colour. Some individuals are solitary and others form aggregations of similar morphotypes. The aggregations include a range of different-sized individuals and are likely to be clones formed by asexual reproduction, possibly by fragmentation when the sea anemone moves across the substrate. The different morphotypes show great resemblance to corals, algae and other objects in the environment and the sea anemone seems to use camouflage, mimicry and masquerade to blend itself into its surroundings, deceive potential prey and confuse potential predators. [5]

Phyllodiscus semoni is a zooxanthellate species of sea anemone, housing symbiotic photosynthetic dinoflagellates within its tissues. These are concentrated in the pseudotentacles which are spread out widely during the day to maximise their exposure to the light. At the same time the oral disc, mouth, and tentacles are retracted into the interior of the animal and it is not apparent that it is a sea anemone at all. At night the oral disc emerges and the tentacles expand to feed on zooplankton and small invertebrates. [5]

Venom

This sea anemone is venomous and its stings can cause painful injuries to humans, and on rare occasions can result in acute kidney damage. [3] The toxin has been shown to kill the shrimp Palaemon paucidens and cause haemolysis in sheep red blood cells. [6] Human contact with Phyllodiscus semoni can cause a severe dermatitis with ulceration and swelling of the affected part which may persist for months. Several haemolytic toxins have been isolated from Phyllodiscus semoni and it is the first sea anemone whose venom has been shown to damage the kidneys and cause acute renal failure. The venom does not appear to affect other major organs. [3]

Related Research Articles

Venom Toxin secreted by an animal

Venom is a type of poison, especially one secreted by an animal. Venom has evolved in a wide variety of animals, both predators and prey, and both vertebrates and invertebrates.

Cnidocyte Explosive cell containing one giant secretory organelle (cnida)

A cnidocyte is an explosive cell containing one giant secretory organelle called a cnidocyst that can deliver a sting to other organisms. The presence of this cell defines the phylum Cnidaria. Cnidae are used to capture prey and as a defense against predators. A cnidocyte fires a structure that contains a toxin within the cnidocyst; this is responsible for the stings delivered by a cnidarian.

Amphiprioninae Subfamily of fishes

Clownfish or anemonefish are fishes from the subfamily Amphiprioninae in the family Pomacentridae. Thirty species are recognized: one in the genus Premnas, while the remaining are in the genus Amphiprion. In the wild, they all form symbiotic mutualisms with sea anemones. Depending on species, anemonefish are overall yellow, orange, or a reddish or blackish color, and many show white bars or patches. The largest can reach a length of 17 cm (6.7 in), while the smallest barely achieve 7–8 cm (2.8–3.1 in).

Anthozoa A class of cnidarians without a medusa stage

Anthozoa is a class of marine invertebrates which includes the sea anemones, stony corals and soft corals. Adult anthozoans are almost all attached to the seabed, while their larvae can disperse as part of the plankton. The basic unit of the adult is the polyp; this consists of a cylindrical column topped by a disc with a central mouth surrounded by tentacles. Sea anemones are mostly solitary, but the majority of corals are colonial, being formed by the budding of new polyps from an original, founding individual. Colonies are strengthened by calcium carbonate and other materials and take various massive, plate-like, bushy or leafy forms.

Sea anemone A group of marine, predatory animals of the subclass Hexacorallia.

Sea anemones are the marine, predatory animals of the order Actiniaria. They are named after the anemone, a terrestrial flowering plant, because of the colourful appearance of many. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and Hydra. Unlike jellyfish, sea anemones do not have a medusa stage in their life cycle.

<i>Condylactis gigantea</i> Species of sea anemone

Condylactis gigantea is a tropical species of ball anemone that is found in shallow reefs and other shallow inshore areas in the Caribbean Sea – more specifically the West Indies – and the western Atlantic Ocean including southern Florida through the Florida Keys. It is also commonly known as: giant Caribbean sea anemone, giant golden anemone, condylactis anemone, Haitian anemone, pink-tipped anemone, purple-tipped anemone, and Florida condy. This species can easily be seen growing in lagoons or in inner reefs as either individuals or loose groups, but never as colonies. They are often used as a model organism along with others in their genus for facultative symbiosis with monocellular algae.

<i>Nemanthus annamensis</i> Species of sea anemone

Nemanthus annamensis, commonly known as the gorgonian wrapper, is a species of sea anemone found in central Indo-Pacific waters.

<i>Epiactis prolifera</i> Species of sea anemone

Epiactis prolifera, the brooding, proliferating or small green anemone, is a species of marine invertebrate in the family Actiniidae. It is found in the north-eastern Pacific. It has a feature rare among animals in that all individuals start life as females but develop testes later in their lives to become hermaphrodites.

<i>Metridium farcimen</i> Species of sea anemone

Metridium farcimen is a species of sea anemone in the family Metridiidae. It is commonly known as the giant plumose anemone or white-plumed anemone. It is found in the eastern Pacific Ocean from Alaska down to Catalina Island, California.

<i>Triactis</i> Genus of sea anemones

Triactis is a genus of sea anemone in the family Aliciidae. It is monotypic, having only one species – Triactis producta. This is found in shallow waters in the Indo-Pacific where it lives on the seabed, rocks and corals. It derives much of its energy needs from the symbiotic algae it contains. It also forms a mutualistic relationship with small Lybia crabs.

<i>Bartholomea annulata</i> Species of sea anemone

Bartholomea annulata is a species of sea anemone in the family Aiptasiidae, commonly known as the ringed anemone or corkscrew anemone. It is one of the most common anemones found on reefs in the Caribbean Sea.

<i>Lebrunia neglecta</i> Species of sea anemone

Lebrunia neglecta is a species of sea anemone in the family Aliciidae. It is found in the Caribbean Sea and Gulf of Mexico.

<i>Actinodendron arboreum</i> Species of sea anemone

Actinodendron arboreum, commonly known as tree anemone or hell's fire anemone, is a species of sea anemone in the family Actinodendronidae. It is native to the Indo-Pacific where it grows at depths of down to 28 metres (92 ft). Most sea anemone species are harmless to humans, but A. arboreum is highly venomous and its sting can cause severe skin ulcers.

<i>Lebrunia coralligens</i> Species of sea anemone

Lebrunia coralligens, commonly known as the hidden anemone, is a species of sea anemone in the family Aliciidae. It is found in shallow water in the Bahamas, the Caribbean, and Brazil. It lives in fissures in corals and rocks.

<i>Dofleinia armata</i> Species of sea anemone

Dofleinia armata, commonly known as the striped anemone or armed anemone, is a species of sea anemone in the family Actiniidae.

<i>Actinothoe sphyrodeta</i> Species of sea anemone

Actinothoe sphyrodeta, the sandalled anemone, is a small sea anemone in the family Sagartiidae. It is native to the northeastern Atlantic Ocean and is common on the north, west and south coasts of Britain. It is usually grey or whitish but may have an orange oral disc. The translucent white tentacles that grow around the edge of the oral disc can number up to 120.

<i>Exaiptasia</i> Genus of sea anemones

Exaiptasia is a genus of sea anemone in the family Aiptasiidae, native to shallow waters in the temperate western Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico. It is monotypic with a single species, Exaiptasia pallida, and commonly known as the brown anemone, glass anemone, pale anemome, or simply as Aiptasia.

Allantactis is a monotypic genus of sea anemones, and Allantactis parasitica is the only species in the genus. This sea anemone lives at bathyal depths in the North Atlantic Ocean and has a symbiotic relationship with a gastropod mollusc.

<i>Corynactis viridis</i> Species of sea anemone

Corynactis viridis, the jewel anemone, is a brightly coloured anthozoan similar in body form to a sea anemone or a scleractinian coral polyp, but in the order Corallimorpharia. It is found in the northeastern Atlantic Ocean and the Mediterranean Sea and was first described by the Irish naturalist George Allman in 1846.

<i>Aiptasia mutabilis</i> Species of sea anemone

Aiptasia mutabilis, also known as the trumpet anemone, rock anemone, and glass anemone, is a species of anemone typically found attached to substrates in cold waters of the Atlantic Ocean. Its unique trumpet shape gives it its common name and it can grow to be 12 cm, having a column between 3 and 6 cm in size. Like many cnidarians, they rely on nematocysts for protection and to capture prey. They are not difficult to care for, and can be kept in a home aquarium, although due to their speed of reproduction, can quickly become overpopulated.

References

  1. Fautin, Daphne (2013). "Phyllodiscus Kwietniewski, 1897". WoRMS. World Register of Marine Species . Retrieved 2014-01-23.
  2. Fautin, Daphne (2013). "Phyllodiscus semoni Kwietniewski, 1897". WoRMS. World Register of Marine Species . Retrieved 2014-01-23.
  3. 1 2 3 Mizuno, Masashi; Nozaki, Masatoshi; Morine, Nobuya; Suzuki, Norihiko; Nishikawa, Kazuhiro; Morgan, B. Paul; Matsuo, Seiichi (2007). "A Protein Toxin from the Sea Anemone Phyllodiscus semoni Targets the Kidney and Causes a Severe Renal Injury with Predominant Glomerular Endothelial Damage". American Journal of Pathology. 171 (2): 402–414. doi:10.2353/ajpath.2007.060984. PMC   1934535 . PMID   17600120.
  4. Fautin, Daphne (2000). "Phyllodiscus, Phyllodiscus semoni Kwietniewski 1897". Tree of Life Web Project. Retrieved 2014-01-23.
  5. 1 2 Hoeksema, Bert W.; Crowther, Andrea L. (2011). "Masquerade, mimicry and crypsis of the polymorphic sea anemone Phyllodiscus semoni and its aggregations in South Sulawesi". Contributions to Zoology. 80 (4).
  6. "Phyllodiscus semoni (Night anemone)". Animal Toxin Annotation Program. UniProt. Retrieved 2014-01-23.